A cigar tunnel (or tunneling), a circumstance in which a cigar’s wrapper leaf doesn’t burn, causing a cave-like formation in the foot of the cigar, can be caused by several factors: First, the binder tobaccos could be to blame. The purpose of the binder leaf is to help all of the tobaccos burn at approximately the same rate. Therefore, if the wrapper is too moist, too thick, or too oily, it may not burn at the same rate as the filler and binder. (Maduro and Oscuro cigar wrappers tend to be much oilier than most shade grown and other “natural” wrapper leaves.)
It’s happened to everyone who smokes premium cigars – the bad burn caused by poor cigar construction. Whether it’s the cigar going out on you too fast, canoeing, or the wrapper coming undone, a bad burn is one of the most frustrating things that can happen. Since a bad burning cigar requires so much extra work, maybe a better word would be “irritating.” Often times, you’ve spent so much time getting the cigar to straighten out, you don’t even remember how the darn thing tasted.
There are several factors that contribute to a bad burning cigar. Some of these I’ve touched on in past articles. For example, it could be the wrapper was too delicate, too thick and oily, or just an inferior quality or poorly cured leaf. Other factors can be a wrapper leaf that’s too dry, which tends to cause the leaf to unravel. It could also be due to poor rolling. Either the bunch wasn’t rolled carefully enough, or during the bunching process some of the binder, which aids in the burning of a cigar, got tucked into the filler. The result is a canoeing cigar, because there’s nothing in those spots to help the wrapper along.